OP0168 A MATRIX RISK MODEL COMPOSED OF SALIVARY ULTRASONOGRAPHIC GLAND SCORE AND OMERACT SCORE ASSOCIATED WITH SALIVARY HYPOFUNCTION OF PRIMARY SJÖGREN SYNDROME
Authors: W. K. Huang, S. Y. Hao, Z. M. Ouyang, X. H. Chen, W. J. Yang, J. S. Chen, L. Dai, Y. Mo
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Salivary gland ultrasonography (SGUS) is promising on diagnosis and disease monitoring of primary Sjögren's syndrome (pSS). However, there is neither study concerning the association between SGUS and salivary function in pSS. <h3>Objectives</h3> This study aimed to explore how SGUS features reflected the secretory function of salivary glands in pSS. <h3>Methods</h3> The subjects who presented with ocular dryness and/or oral dryness were recruited from rom July 2021 to July 2022 at our department. The subjects were classified as pSS and non-SS according to the 2002 the American-European Consensus Group (AECG) criteria for pSS. Unstimulated whole salivary flow (UWSF) and stimulated whole salivary flow (SWSF) were assessed to evaluate salivary function. SGUS was performed to bilateral parotid and submandibular glands. Each gland was assessed by a well-accepted 0–4 scoring system (gland score) and a 0-3 scoring system from the Outcome Measures in Rheumatology Clinical Trials working group (OMERACT score). <h3>Results</h3> ① Among 309 enrolled subjects with suspected pSS, 95 subjects were excluded due to being classified as secondary SS, or failing to receive the designated SGUS examination or labial salivary glands biopsy. Therefore, 214 subjects were qualified for statistical analysis, including 116 pSS patients. The mean age of pSS patients was 47.1±13.3 years old and 97% of them were female, age-match and sex-match to the non-SS controls. ② Compared to the pSS patients without hypofunction, pSS patients with salivary hypofunction (n=71, SWSF ≤0.7mL/min) were significantly older, higher positive rate of the Van Bijsterveld score, higher positive rate of anti-SSA/Ro, higher incidence of UWSF≤0.1mL/min and lower incidence of thrombocytopenia (all <i>p</i>&lt;0.05). ③ The pSS patients with salivary hypofunction had significantly higher total OMERACT score (10 [<i>interquartile range (IQR</i>), 8-12] vs. 8 [<i>IQR,</i> 6-8], <i>p</i>&lt;0.001), and total gland score (12 [<i>IQR,</i> 10-12] vs. 8 [<i>IQR,</i> 6-11], <i>p</i>&lt;0.001) than the patients without salivary hypofunction (Figure 1A). ROC curve confirmed total OMERACT score (<i>AUC</i>: 0.804, 95%<i>CI</i>: 0.727-0.881, <i>p</i>&lt;0.001) and total gland score (<i>AUC</i>: 0.792, 95%<i>CI</i>: 0.704-0.881, <i>p</i>&lt;0.001) could significantly distinguish pSS patients with salivary hypofunction from those without salivary hypofunction. The cut-off values of total OMERACT score were 7 and 9, and of total gland score were 9 and 11, according to the Youden index. The absolute value of SWSF in the pSS patients with total gland score &gt;11 was significantly lower than those with total gland score of 9~11 or total gland score &lt;9 (both <i>p</i>&lt;0.05). The absolute value of SWSF in the pSS patients with total OMERACT score &gt;9 was significantly lower than those with total gland score of 7~9 or total gland score &lt;7 (both p&lt;0.001, Figure 1B). ④ Total OMERACT score and total gland score were combined to generate a 3×3 matrix model and then the estimated risk probability for salivary hypofunction of pSS was calculated in each grid (Figure 1C). Accordingly, pSS patients could be stratified into three risk subgroups: (i) High-risk (n=39): pSS patients whose total OMERACT score was &gt;9 and total gland score ≥9 had estimated risk probability greater than 80%, and the actual incidence of SWSF≤0.7mL/min was 95% (37/39). (ii) Low-risk (n=28): pSS patients whose total OMERACT score was &lt;7; or whose total OMERACT score was 7~9 and total gland score &lt;9 had estimated risk probability less than 35%, and the actual incidence of SWSF≤0.7mL/min was 14% (4/28). (iii) Moderate-risk (n=49): pSS patients who fulfilled neither high-risk nor low-risk had an actual incidence of SWSF≤0.7mL/min in a moderate level (61%, 30/49). <h3>Conclusion</h3> This study first reported B-mode ultrasonography examination on four major salivary glands could reflect salivary function of pSS. We also built a matrix risk model composed of SGSU gland score and OMERACT score associated with salivary hypofunction in pSS which was conviently used for rheumatologists, especially in specific clinical situations that SWSF was not available. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.